The present invention relates to electronic packaging, and more particularly to a lead frame package that is configured to mount an electronic device for a vehicle thereon, and a method for manufacturing the same.
As is well known, vehicles typically include a number of sensor devices mounted at various locations for measuring certain physical parameters and providing electrical signals for electronic control or for providing a warning message to the occupant. Such sensors include acceleration sensors, wheel speed sensors, slope sensors, knock sensors, vehicle speed sensors, temperature sensors, air pressure sensors, and the like. Typically, the sensors are assembled as a packaged structure configured for mounting to the vehicle.
An electronic sensor package for a vehicle typically is manufactured through a series of process steps, which includes attaching an electronic sensor chip onto a die paddle of a lead frame. The lead frame typically has a plurality of leads that surround the die paddle. The manufacturing process also includes forming a continuous molded frame that surrounds and encapsulates the lead frame, connecting the respective leads to corresponding bond pads located on the electronic sensor chip through conductive wires and sealing the respective leads and the electronic sensor chip with a cover. Such a process is described, for example, in Korean Unexamined Patent Publication No. 2012-0070213 (published on Jun. 29, 2012). In order to protect the electronic sensor chip from the harsh environment internal and external to the vehicle, the cover in the related packages is configured as a solid piece of material without holes, which attaches to the molded frame to form a sealed structure. One problem with this package structure is that the cover may become tilted or may separate or rotate away from the rest of the structure during assembly. It is believed that this defect is caused by air pressure build-up when the cover is attached to seal the electronic sensor device. This defect can cause reliability problems because, among other things, the electronic sensor is exposed to the harsh environment.
Accordingly, it is desirable to have a structure and method that improve the reliability of electronic sensor packages including those configured for vehicle applications.
For simplicity and clarity of the illustration, elements in the figures are not necessarily drawn to scale, and the same reference numbers in different figures denote the same elements. Additionally, descriptions and details of well-known steps and elements are omitted for simplicity of the description.